Re: 7mm STW and vv n570
I've no experience loading for the 7mmSTW. I modeled the 168g Berger/7mmSTW in QuickLOAD, had it develope a load map, and took a look just for fun. QL says 73.0g of N560 is a max load. I'd back off, load one round at 70, and in half grain increments up to 73.5 and watch for pressure signs. Pull the rest of the bullets if you see signs and go at it from there.
FWIW: QL also predicts slightly more MV with Retumbo, H870, and the most MV with N570.